All potentially compatible people can be separated into two categories. The first category consists of all the people that one is not aware of because one has not met them, seen them, or even heard of them. This is the group addressed by online dating services, newspaper personal ads, and match makers in that they alert the individual to the existence of specific other individuals who may be compatible.
Newer technological developments that serve this same population are hand-held devices such as the Japanese Lovegety and the Spotme device that alert the user to potentially compatible people in the user's immediate environment that would have otherwise gone unnoticed. Even more recently a cellular telephone company, AT&T Wireless, in conjunction with an online dating service, Match.com, has offered a profile matching service to cellular telephone users that is activated when users are in the same physical proximity. All of these services alert the user to potentially compatible partners that the user otherwise would not know about.
The second category of people consists of all the people that one does in fact already know about because one has already met them, heard of them, or at least seen them. This group includes friends, classmates, colleagues, acquaintances, and the largest group—strangers that one becomes aware of in the normal course of everyday activity in a grocery store, elevator, subway train, restaurant, etc.
When it comes to having a relationship with someone among this second category, one is usually aware of which individuals one is interested in and which individuals one is not interested in. In this case, the issue then is not who to date, but rather how to go about making that happen. There is, therefore, a need to facilitate developing relationships with the people that one is already interested in.